Actually Sri lanka and other asian teams hardly survive in the fast pitches of Australia or Africa or even England. Pakistan is doing really well though I have to say, considering they don't have any teams touring them. Yet maintaining a ranking
It is not entirely true as India has played matches and won in England and Australia and they have the best record outside the continent when you compare the teams in Asia and Pakistan is playing in neutral pitches in the UAE and was winning matches and so is the reason they are ranked higher .Every team is strong when they are playing in their home ground so there is nothing surprising about it.
To be honest India have not won many matches in Australia only 5 test matches since they started playing in Australia in 1947/48 and like I said since that time they have only won 5 test matches which is poor. They have never won a test series in Australia where as Australia has won 4 test series playing in India with a few drawn test series as well. So I can see where some people are coming from when they say that Asian teams can't play well on fast pitches.